Another paper that was published in June was a study that used the Arecibo incoherent scatter radar to show that thermal plasma-line profiles can be observed up to the top-side of the ionosphere. Our results address a fundamental theory of scattering of electromagnetic waves from thermal plasma, which was formulated in the 1960s. The theory has so far been validated only partially, for the ion line component of the theory, which describes scattering from ion acoustic waves. Our new measurements confirm for the first time that the second part of the theory, which describes scattering of electromagnetic waves from thermal plasma waves, also known as Langmuir waves, is also accurate to with a factor of 2, when comparing the relative power of the ion line and the plasma line.